Lens



March 6, 1934. A, TULMIN, JR 1,949,698

LENS

Filed May 18 1931 2 Sheets-Sheet 1 F463. 177461.44.` .17116.5. Flo.1716.7.'

6Min

March 6, 1934. H A TQULMlN, JR 1,949,698

LENS

Filed May 18, 1931 2 Sheets-Sheet 2 I3 Y 2l :f1/5.11` l F16- 1/ L -w A IFlei. F1614. F1615. 1 4 FusJw Patented Mar. 6, 1934 UNITED STATES PATENTOFFICE The Univis Corporation, W

corporation of Delaware y Application Mayu18, 1931, Serial No. 538,066

6- Claims.

My invention relates to eyeglass lenses.

It is the object of my invention to provide a bifocal eyeglass lens, inwhich the reading segment can have its maior vertical plane tilted toany desired angularity for the dual purpose of eliminating any prismaticeffect when the vision of the wearer passes from the distance section tothe near distance or reading section and for the second purpose ofthrowing the prism up or down 1. in order to locate the optical centerwhere it may be desired.

It is my object te provide a method of fsing an insert, preferably ofcomposite character of flint and crown glass, in a crown glass support,

1g such insert being uniform in section and in size so as to giveuniformity of production.' but which, according to the tilted positionof the insert within the countersink of the major lens, will give theforegoing results.

It is an important object of my invention to provide means ofsoriountinga near vision insert that I can throw the optical center ofthe near vision insert at any position in its vertical height whilestill maintaining the original outg5 line of the optical insert. C

It is a further object to be able to use a relatively thin major lenswith a relatively large and easily adjusted insert in` which the inserthas a back of the same glass as that of the major lens 3g so that thedeficiency -in thickness of the major lens may be made up by the fusingthereto of the backing of the insert while, at the same time, permit ofthe use in the insert of su'ch large size that it is easily adjusted andtilted in order to control the proper position of the insert for neardistance vision.

Referring to the drawings:

Figure 1 is a front elevation of the major lens with the countersink cutin the face thereof; Figure 2 is a front elevation of the lens with thebutton in position prior to fusing;

Figure 3 is a vertical section through the insert on the line 3 3 ofFigure 2;

Figure 4 is a section on the line 4 4 of Figure 5 2 showing the positionof the insert with the insert tilted to throw the prism down;

Figure 5 is a. similar view with the insert tilted to throw the prism upFigure 6 is a section through the finished lens showing the prism down;

Figure 'I is a similar view showing the prism 11i);

Figure 8 is a front elevation of the finished lens showing itsappearance either in the form ofFisureSorFigure'inwhichthe form-ofthezonal insert is not changed by throwing the prism up or down, while, atthe same time, secure that result and thereby controlling the opticalcenter of the insert;

Figure 9 is eseeuen through the insert comeo the une 14-414 of prisingthree blocks of glass, two of .which are composed of two blocks of glassfor the formation Figure 1l is a plan view Figure 12 is a frontelevation of the first stage Figure 13 is a section on the line 13-13 ofFigure 12;

Figure 16 is a section on the line 16J-16 of ton shown in Figure 19:

Figure 19 is a.- front elevation of the completed Referring to thedrawings 4in detail, 1 is a maior at 3. I mount in thisspherically-curved deprescurved face to that of the depression 2 in theWhen I refer to "crown and flint" glass I 9 refraction.

pieces of glass which are thus made for concountersink 2., 05

spherically-curved back surface 4 and a fiat front of crown glass andone of flint for the insert:

Figure 10is a similar view showing the insert' of the segmental insertshown in Figures 17, 18 a5- and 19;

i of a backing plate of raw glass;

of manufacture of the insert before chipping and 70 before theapplication of the backing plate;

Figure 1l;

Figure 14 is a section on Figure 15 is a front elevation of the chippedinsert shown in Figure 12;

Figure 17; v

Figure 17 is a front elevation of the insert but so Figure 18 is asection on the line 18-18 oi? Figure 19:

lens with the insert fused therein from a button shown in Figure 17.

lens having a countersunk portion or sphericallycurved depression 2 thatis circular in outline as sion a button comprising flint and crownglass. such button having a correspondingly sphericallymain or majorlens 1 which is also made of crown glass.

comprehend within my invention any glass suitable for the purpose havingdifferent indices of This spherically-fcurved face is designated 4. 10o'The button itself is composed of a" plurality of venience and thenfused together as. a composite -button before insertion of the button inthe- 1 In the form shown in Figures 3, 4. 5, 6. 'I and 8, the insertcomprises a back plate 5 having the surface 6. such back plate beingcomposed of crown glass. A rectangular block ofI flint :las ,'l x10occupy. In doing so it is preferable to provide the face 8 parallel tothe line of vision 11 from the eye at 12 so that the line of vision ofthe eye, while looking downwardly from the horizontal line 13 below thatline at distant objects, will not pass through any prismatic corner ofthe insert 7, and when the line of vision l1 lowers further, it willimmediately pass Without distortion and without delay into the segment'l with full reading value and with full width of a reading areaprovided by the segment 7, as will be more fully seen in Figure 8.

If the insert is rocked as in Figure 5 instead of the line 11 passingparallel to the surface 8 of the insert 7, it will pass above theforward edge of the surface 8 of the insert 7 but with the same result,irrespective of the fact that the optical center has now been thrownupwardly instead of downwardly when the lens is ultimately ground.

As a result of this arrangement of rocking the insert, it is possiblenot. only to avoid very largely prismatic displacement at the edge ofthe insert, but the more important object is obtained of throwing theoptical center of the insert where desired while, at the same time, notchanging the form of the segmental insert as to its major outline. Thus.uniformity of appearance of the lenses is provided and uniformity ofoutline so that the wearer may become accustomed to a form of insert andnot be disturbed by changes in that form due to changes in prescription.When an insert, such as shown in Figure 8, is utilized, this result isachieved from the invention in addition to the other advantages thatflow from the important fact that, if desired, the segment may be sorocked that the line of vision through the optical center will be atsubstantially right'angles to the vertical plane of the insert. v

In the form shown in Figures 3, 4, 5. 6 and rI where the major lens isto be extremely thin, the insert may extend approximately to the back ofthe lens or if it is desired to use a thicker lens and a thicker insert,then the form of insert shown in Figure 7 can be employed.

In making up this insert, I find it sometimes desirable to use a sheetof raw glass or crown glass, such as shown in Figure 11, then toassemble rectangular bars of crown and flint glass, as

` in Figure 12, and to fuse the two assemblies together as shown inFigures 13 and 14. I then grind the back of the composite insert to theproper curvature after having chipped the insert to its general circularformas in Figure 15.

I follow the same procedure when making an insert' such as shown inFigure 10 by first assembling the several parts of the insert in therough form, as in Figure 16, after chipping to the general circular formas shown in Figure 17, and grinding the backing as in Figure 10,mounting in position in the main lens and fusing. I then have a lens asshown in Figure 18.

In this particular form of segment, the top 14 may be rocked up parallelwith the line 11 as at Figures 4 and 5 which it is desired that theblock 'I should ultimately as in Figure 4 or arranged as in Figure 18.By rocking the segmentv the optical center can be adjusted vertically. Y

It will be understood that I desire to comprehend within my inventionsuch modifications as may be necessary to adapt it to varying conditionsand uses. l

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is:

1. In a method of manufacturing a lens, providing a major lens of oneindex of refraction having a spherical-curved countersink in the facethereof, securing therein a button of larger diameter than saidcountersink having an inserted portion of a different index ofrefraction imbedded in the front face thereof and extending partiallytherethrough, said button having a spherically-curved face engaging thecountersink face, rocking said button.to a predetermined desiredposition to adjust the position of the optical center in the resultinglens, fusing the button in the countersink of the first mentioned lenswhile in said rocked position, and grinding the resulting lens wherebythe optical center is adjusted without changing the outline of theinsert of the different index of refraction.

2. A new article of manufacture for use as an insert button in a bifocallens comprising a rectangular block of flint glass, a block of crownglass behind said flint glass, and blocks of crown glass on either sideof said flint glass, said blocks being fused together and the rearsurfaces thereof being ground to the surface of the sphere.

3. A new article of manufacture for use as an insert button in a bifocallens comprising arectangular block of flint glass, a block of crownglass behind said flint glass, and blocks of crown glass on either sideof said flint glass, said blocks being fused together and the rearsurfaces thereof being ground to the surface of the sphere, the top andbottom edges of said flint block being greyed.

4. In a method of manufacturing a bifocal eyeglass lens, providingablock of int glass, fusing blocks of crown glass on the top and bottomedges thereof, fusing a block of crown glass on the back of said threeblocks of glass, imparting a surface constituting a part of a sphere tothe back of said crown glass blocks, inserting the compositey insert in'a major lens of crown glass having a concave receiving surface, rockingthe flat face of said insert with respect to the vertical plane of saidmajor lens to adjust the position of the optical center of the flintglass insert, fusing the insert into the major lens, and grinding thelens.

5. In a method of manufacturing a bifocal other, moving said buttonrelative to said countersink to place said flint glass insert in apredetermined angular position, and securing said button within saidcountersink while in said displaced arrangement.

6. In a method of manufacturing a bifocal *eye glass lens, providing amajorlens with a spherically-curved countersink, providing a. button ofa larger size than said countersink by button within said countersinkwhile in said displaced arrangement, and surfacing the exposed commonsurface of said button and said major portion to a uniform continuouscurvature whereby the optical center of said insert is placed in apredetermined position.

HARRY A. ToULMrN, Jn.

